<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!--这里可以直接用link加上tab-->
    <link rel="stylesheet" href="1-css.css" type="text/css">
</head>
<body>
    <div  >one</div>
    <div  >two</div>
    <span  >three</span>
</body>
</html>